If a train derailed near the Mississippi River between Wisconsin and Minnesota, spilling some 150,000 gallons of crude oil into the water, it would be a disaster of immense proportions.

A spill of such magnitude would require a huge response, one that would involve equipment and people from the federal government and agencies in three different states — Wisconsin, Minnesota and Iowa — La Crosse Fire Captain Jeff Schott said.

"That would be private, all public entities, all the way up from Minneapolis, all the way down to the Quad Cities," he said. "You're talking months. So we would have to be diligent about making those contacts and getting them all here. La Crosse would be a busy place for a while."

Emergency responders attempt to bring in an oil containment boom on the waters of the Mississippi River Friday in La Crosse, Wis.Alex Kolyer / For MPR News

With that in mind, for the first time nearly 100 federal, state and local emergency responders are training this week on how to handle such a spill, a response to the rapidly growing rail shipments of crude oil from North Dakota that pass by the Mississippi.

In February, a Canadian Pacific train spilled about 12,000 gallons of crude oil along 70 miles of track between Red Wing and Winona. The Minnesota Pollution Control Agency required the company to clean up portions of the spill where puddles of oil accumulated, even though the oil did not seep into the river.

During a drill on Friday, crews fought wind and waves to pull a 300-foot boom away from Target Lake. The lake is within the Upper Mississippi River National Wildlife and Fish Refuge near La Crosse. Workers had set up the giant rope-like structure hours earlier as part of the simulated oil spill.

Heidi Young and Eric Bankes help pull in an oil containment boom outside La Crosse, Wis. A coalition of federal, state and local emergency responders conducted training to prepare for a large-scale oil on the Mississippi River Friday.Alex Kolyer / For MPR News

"We have this whole bunch of backwater area between Minnesota and Wisconsin here," said Jim Stockinger, an emergency response specialist for the MPCA, as he considered what would happen in a real oil spill. "We're trying to keep oil out of these back water areas 'cause they're incredible habitat areas for various birds and fish and all kinds of wildlife and getting oil into there would be tremendously hard to clean up."

The agencies chose the riverfront site to practice responding to an oil spill because of its ecology of backwater marshes and floodplain forests. The area is also home to flocks of migratory birds, and is a popular hunting and fishing area.

Concerns about spills and other accidents have led to greater scrutiny of train traffic and calls for more action on the part of state and federal officials.

Stockinger said the training marks the first time so many agencies and railroad companies have come together to practice deploying booms, learning how to clean oil-covered wildlife and training in communication and organization — techniques that they likely will need to use some day.

Paul Wolf, of USDA Wildlife Services, demonstrates the use of a net gun on decoy geese Friday during a drill in La Crosse, Wis. The nets could be used to capture wildlife, if necessary, in an emergency response situation.Alex Kolyer / For MPR News

"It's not a matter of if, it's a matter of when and it's a matter of where," he said. "Railroads have a tremendous safety record. They'll tell you 99.997 percent of their cargo gets to its destination without incident. And that's a number I think we can all believe and be confident in. But as an emergency responder in this field, I only care about the 0.003 percent."

If there, those who direct the cleanup will have to ensure that all of the responders work together, said Lisa Olson-McDonald, west central regional director for Wisconsin Emergency Management.

"It might not be one head person, but there will be one person from police, one person from fire, one person from fish and wildlife," she said. "And they'll get together in this unified command."

On Friday, crews found moving equipment to the site of a spill proved more challenging than they thought.

An emergency responder helps maneuver an oil containment boom from shore during practice drills on the Mississippi River Friday in La Crosse, Wis.Alex Kolyer / For MPR News

If there were a spill involving BNSF Railway, the company would deploy its own equipment and contractors to help with clean up, said Amy McBeth its director of public affairs.

"We're working with the La Crosse fire department on ... an agreement to stage additional equipment here," she said. "That's in the works and we're hopeful that we'll get that agreement soon and that would include a fire trailer and two spill trailers."